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author | Roland McGrath <roland@hack.frob.com> | 2014-07-07 09:28:38 -0700 |
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committer | Roland McGrath <roland@hack.frob.com> | 2014-07-07 09:28:38 -0700 |
commit | 08192659bbeae149e7cb1f4c43547257f7099bb0 (patch) | |
tree | 9f602a4e9f0aefdb06bc15a76be46e958e91a58f /nptl/sem_post.c | |
parent | 96baf6ffc57b811bbc424a1fc72ef77dd56d7a18 (diff) | |
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Get rid of nptl/sysdeps/ entirely!
Diffstat (limited to 'nptl/sem_post.c')
-rw-r--r-- | nptl/sem_post.c | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/nptl/sem_post.c b/nptl/sem_post.c new file mode 100644 index 0000000000..4906adf332 --- /dev/null +++ b/nptl/sem_post.c @@ -0,0 +1,80 @@ +/* sem_post -- post to a POSIX semaphore. Generic futex-using version. + Copyright (C) 2003-2014 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Jakub Jelinek <jakub@redhat.com>, 2003. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <atomic.h> +#include <errno.h> +#include <sysdep.h> +#include <lowlevellock.h> +#include <internaltypes.h> +#include <semaphore.h> + +#include <shlib-compat.h> + +int +__new_sem_post (sem_t *sem) +{ + struct new_sem *isem = (struct new_sem *) sem; + + __typeof (isem->value) cur; + do + { + cur = isem->value; + if (isem->value == SEM_VALUE_MAX) + { + __set_errno (EOVERFLOW); + return -1; + } + } + while (atomic_compare_and_exchange_bool_rel (&isem->value, cur + 1, cur)); + + atomic_full_barrier (); + if (isem->nwaiters > 0) + { + int err = lll_futex_wake (&isem->value, 1, + isem->private ^ FUTEX_PRIVATE_FLAG); + if (__builtin_expect (err, 0) < 0) + { + __set_errno (-err); + return -1; + } + } + return 0; +} +versioned_symbol (libpthread, __new_sem_post, sem_post, GLIBC_2_1); + + +#if SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_1) +int +attribute_compat_text_section +__old_sem_post (sem_t *sem) +{ + int *futex = (int *) sem; + + (void) atomic_increment_val (futex); + /* We always have to assume it is a shared semaphore. */ + int err = lll_futex_wake (futex, 1, LLL_SHARED); + if (__builtin_expect (err, 0) < 0) + { + __set_errno (-err); + return -1; + } + return 0; +} +compat_symbol (libpthread, __old_sem_post, sem_post, GLIBC_2_0); +#endif |